(1) Field of the Invention
The present invention relates generally to portable, self-contained vehicle tracking and monitoring systems, and more particularly to an improved orientation-based wireless sensing apparatus for sensing several conditions of a railcar or other vehicle using accelerometers.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97, 1.98
There are many problems and challenges for inventors to create a viable wireless sensing device for detecting a variety of different conditions of a vehicle or load using a single configuration of the device. Attempts have been made but no one has created a device to solve all of the problems.
First, the device must have low power requirements because railcars have no electrical power and the devices are subject to long-term use before being conveniently accessible to replace the power source.
The tracking unit must also be rugged and physically last a long time. Rail cars are constantly exposed to the elements, including salt spray, and are subjected to various shocks and vibrations during loading, sorting, and movement about the country.
Because there are many different types of conditions on a railcar that it is desirable to monitor, including: (1) whether the car is loaded or empty, (2) whether a hatch is open or closed, (3) whether a handbrake is set or released, (4) whether a door is open or closed, etc., it is important that the detectors have the ability to sense a variety of different motions or positions of critical vehicle features.